This Common Activity Is Reducing Your IQ, According to Research

The performance gap caused by an hour’s difference in sleep was bigger than the gap between a normal fourth-grader and a normal sixth-grader. Which is another way of saying that a slightly-sleepy sixth-grader will perform in class like a mere fourth-grader. “A loss of one hour of sleep is equivalent to [the loss of] two years of cognitive maturation and development,” Sadeh explained.

Teens who received A’s averaged about fifteen more minutes sleep than the B students, who in turn averaged fifteen more minutes than the C’s, and so on. Wahlstrom’s data was an almost perfect replication of results from an earlier study of over 3,000 Rhode Island high schoolers by Brown’s Carskadon. Certainly, these are averages, but the consistency of the two studies stands out. Every fifteen minutes counts.

Not only does it affect intelligence, lack of sleep also reduces impulse control.

A different mechanism causes children to be inattentive in class. Sleep loss debilitates the body’s ability to extract glucose from the bloodstream. Without this stream of basic energy, one part of the brain suffers more than the rest—the prefrontal cortex, which is responsible for what’s called “Executive Function.” Among these executive functions are the orchestration of thoughts to fulfill a goal, prediction of outcomes, and perceiving consequences of actions. So tired people have difficulty with impulse control, and their abstract goals like studying take a back seat to more entertaining diversions. A tired brain perseverates—it gets stuck on a wrong answer and can’t come up with a more creative solution, repeatedly returning to the same answer it already knows is erroneous.

And when we’re tired it’s actually harder to be happy. We can recall negative memories more than positive ones when we’re exhausted.

5 Horrible Habits You Need to Stop Right Now

Do Not Email First Thing in the Morning or Last Thing at Night “The former scrambles your priorities and all your plans for the day and the latter just gives you insomnia,” says Ferriss, who insists “email can wait until 10am” or after you check off at least one substantive to-do list item.

Chris Pecoraro—Getty Images

Do Not Agree to Meetings or Calls With No Clear Agenda or End Time “If the desired outcome is defined clearly… and there’s an agenda listing topics–questions to cover–no meeting or call should last more than 30 minutes,” claims Ferriss, so “request them in advance so you can ‘best prepare and make good use of our time together.'”

Sam Edwards—Getty Images/Caiaimage

Do Not Check Email Constantly Batch it and check it only periodically at set times (Ferriss goes for twice a day). Your inbox is analogous to a cocaine pellet dispenser, says Ferriss. Don’t be an addict. Tools like strategic use of the auto responder and Boomerang can help.

Jetta Productions—Getty Images

Do Not Carry a Digital Leash 24/7 At least one day a week leave you smartphone somewhere where you can’t get easy access to it. If you’re gasping, you’re probably the type of person that most needs to do kick this particular habit.

by nacoki ( MEDIA ARC )—Getty Images/Flickr RF

Do Not Let People Ramble Sounds harsh, but it’s necessary, Ferriss believes. “Small talk takes up big time,” he says, so when people start to tell you about their weekends, cut them off politely with something like “I’m in the middle of something, but what’s up?” But be aware, not everyone agrees with this one (and certainly not in every situation), and you may want to pay particularly close attention to norms around chit chat when traveling internationally.

Negative stimuli get processed by the amygdala; positive or neutral memories gets processed by the hippocampus. Sleep deprivation hits the hippocampus harder than the amygdala. The result is that sleep-deprived people fail to recall pleasant memories, yet recall gloomy memories just fine. In one experiment by Walker, sleep-deprived college students tried to memorize a list of words. They could remember 81% of the words with a negative connotation, like “cancer.” But they could remember only 31% of the words with a positive or neutral connotation, like “sunshine” or “basket.”

TIME Ideas hosts the world's leading voices, providing commentary on events in news, society, and culture. We welcome outside contributions. Opinions expressed do not necessarily reflect the views of TIME editors.

SPONSORED FINANCIAL CONTENT

You May Like

Read More

Sign Up for Our Newsletters

Sign up to receive the top stories you need to know now on politics, health and more